Exhaust steam injector



April 2, 1935.

E. RAWSON ET AL EXHAUST STEAM INJECTOR Filed April 10, 1933 INVENTOR ATTORNEY 2 Sheets-She'= t 1 Patented Ap -1 1935 r v a V, EXHAUST sT M-IN EG OR' h majnuel- Rawson, Nbr flBe a d Jos I w I #3 Grifiin, Teaneok, N. J; ass'ignors toTheSu perheatcr company, New York, N.,

.Application-Qpril 1o, 1933 'Serial No.. 665;2 l6 3 f gt Claims. (0140 3465) The present invention relates to exhaust steam injectors and has particular reference to exhaust steam injectors of thejmultiple-istage' type for delivering 'boiler feediwater against relatively high boiler pressures. Still more particularly the invention relates to two-stagegexhaust steaminjectors of the type in whichjjthe, low; pressure stage is operated by exhaust steain from amen- "gine {when s'uchsteam; is available and is op-Y 'erated bylow pressure'live steam (when exhaust steam is not available, and in which theihigh,

pressure stage is operatedby "high pressure live steam at all timeswhenf the injector isin opera "I non.

When' injectors of the above general type. are

jecto'r isinterrupted vdue l to breaking offthe injector. This difiiculty can be understood easily when it is realized that the .first or low'pressure stage is. responsible for the supply of. water 1m the second or high pressure stage. Because Iof this factor, unstable "conditions of operation -in the low pressure stage may causethe supply of Water to the second stage to beinterrlupted, thus causing the high pressure 's'tage to break: with resulting, interruption of delivery of waterbyj the injector. Furthermoregwhenfit is consideredthat the low pressure stage'must workwith exhaust steam, the pressure of which may fluctuate between wide limitsgit will be appreciated that troublesome unstable conditionsof operation of the low pressure stage mayieasily arisegfUnstable operation of the lowpressure stage'is particularly likely to occur when change-over of operation of "the injectorfifrom I exhaust stea'm' operation to live steam operation, or the reverse, takes place. I f

When change-over to exhaust steam operation occurs, exhaust; steam is substituted for live steam 'inthe low pressure stagel' While this substitution may require a [time of only'fia .few seconds, the interval may be suflicient to cause momentary spillingat the over-flow of the low pressure stage "which is reflected in an interruptedwater supply I or, delivery to the, high 'pressures't'age'. During this period of interruption, the high'prs'sure stage lacks the water necessaryto condense thehigh pressure live steam admittedthe'reto; andthis stage, therefore, breaks and its action cannot' be restored without first. shutting 'ofi the entire injector and. re-starting it.. .gFurthermore, in restarting the injectoror fact whenstarting "stage;

' stability of operation of the low pressure stage the injector. The detailed nature 'of'the inven in conjunction-with the accompanying drawings 7 Fig. 2 is a section on enlarged scale of afvaite' shown'in Fig.1? 7

'low pressure stage indicated generally at B and theinjector anytime, the operator must be careful not to admit operating steam to the high pressurebstage until stable operating conditions have been established in the low pressure stage.

so as to provide a deliveryoffwater to the high 5 'pressure'stage; Otherwise the high pressure,

stage will fail-to function because of ;1ackof water to 'conderisethe steam admitted tothis The general object of the bresent'iilvemion is to' 'provide meansfor eliminating the difiiculties of the above-described charactenand this general object'isIlattained-bythe provision of means acting in responseto an'impulse indicative of.

of the injector forcontrolling'the admission of 7 operating steam to the highgpressure stage or tion, together with the more detailedjobjects thereof, andthe manner in which IthBSQ objects are attained Imay best be understood iromthem following description vof formsof'apparatussuit V able for carrying the invention into effect, :taken forming a partof this specification; a I the drawings; Fig.1g1 is a more or lessjdiagrammatic side elevation, partly in section; showjector embodying theinven'tion; J

'ing the application to a locomotive of an in 7' Fig. 3 is a section r part or; seesaw similar to that shown in Fig. l andadaptedto actuate a form of valve somewhat' different from that a 5 9w L QrZ;

Fig. '4'is a' view partly in sectionuof a'val'vje I similar to the valve shown n i -.2 but adapted to operate with .an, injector of the formshown,

inFig. 3; and f a Fig. 5 islan elevation partly'jin sectionfshowja 7 ing' still anotherform of injector and. control valve arrangement. '1 7 Referring now to Fig. ,1, the injector, indicated generally at A; is of known type andcomprisesa a high pressure stageindicated generally at; C;

- Water is admitted toQthe 10w pressure'tstage from i the supply pipe l0 controlled by the valve I2 manually operable by means of the control handle 14 l 'i 1 located in the 'cab' of 'thelocomotive, -which' is v u 7 indicated generally at D. L'o'w pressurejsteam is admittedv to. the lowi'pressuref stage through the steam" supply pipe. [6 leading froxn' the ex- 'haust passage of the engine cylinder l 8 and in communication with the low pressure steam "a p ,vnection itis ito be noted that because or. this ar- .lishes ajet which results in delivery of water; under pressure to chamber 52 and to'the combin- .ing nozzle 54 of the high pressure stage. As soon as this is accomplished, the pressure fromchamrangementasingle manually ioperable, startingvalve 30, admitting all of .the. high pressure ,live

steam neededgby the injector toga singlesupply pipe 28, is'all1that is required in orderto have a; structure which insures against difficulty. or im-- possibility of starting the. lowpressure stage of, the injector due to the blow into this stage of high pressure steam intended for the actuation of the, high pressure stage. After the admission of water andalow pressure steam'to the low pressure stage of the injector, this stage of the injector-estabber 52, transmitted .throughtheconnection I2 to the chamber 98 of the. automatic valve E, closes the pin valve 92. When valve 92 is closed, high.

pressure: steam leaking throughthe passage 88 Let itfnow be assumed with the injector operating that -the locomotive engine is started and exhaust steam becomesavailable. The portion of the control"system comprising valves 36 and 40 operates automaticallyto closethe live steam admission valve 36 and open the exhaust'valve 40, butduririg this change-over period there may be some interruption in the continuity in the supply of low pressure steam through'pipe Hi. If this interruption in the supply of operatingsteam to the low pressure stage is suflicient to cause the low pressure stage to commence'spilling through the over-flow and to'cease normal delivery of water to the high pressure stage; the failureof delivery pressure chamber 52 will result-in opening of the vent passage inthe automatic valve E and consequentclosin'g of this valve. This automatically prevents the'continued supply of high pressure operating steam to the high pres sure stage, which under the conditions assumed is not receivingits normal supply of'water from the loWpressure stage. Assoon as the low pressure. stage of the injector recommences operation on exhaust steam and water supplied by this stage to the high pressure stage, the automatic valve E again permits high pressure operating steam to flow to the high pressure stage of the injectorand normal operation of the injector recommences without manipulation of the. control on the part ofthe'operator. Itiwill be evidentthat lupon change-overof the injector back to ;live steam operation,'in, caSe..fihe engine throttle is closed, the automatic valve E will function intne manner above described in case .thechange-over results in ,sufficient interruption in the continuity of the supply of low pressure steam ;to'the injector to cause the low pressure stage thereof to spill and-cease to deliver a normal supply of water I tothe highpressure stage.

,;In; the hereinabove '"described embodiment of the invention. the factor. indicative of, stability of operation of thelow pressure stage of theinjectorwhich is employed toprovide the impulse for actuating or controllingthe automatic, valve controlling-the supply of live steam..to. thehigh of the low pressure stage of the injector.

sure of'the low. pressure stage. .Itis wellknown thatthepressure in the overeflowjchamberjof,

an injector. is indicative of the stabilityofxopera! tion of the injectorhzand inl the-nexerciserofithe: present invention over-flow pressure rather than delivery pressure (may, be P employed lto. control I V the action of the valve for.controllingadmission '5 of live steam to theinjector. :1 .i. Y 1' In the present state "of developmentjof ,multiple-stage exhaust: steam injectors of the: 1 general typedisclosed in Fig; 1,.the-low pressure stage ofthe injector does notdeliver water heated to agtemperature above thevaporizing temperature" at atmospheric pressure andlthe pres gsure in the over-flow chamber'under conditions .pressure,stage of the ihjector-isthe delivery pres-,,

of stable operation isless thanatmospheric. In

other Words,',when this stage of thefinjeetoris operating normally a partialvacuumuexists: in

the over-flow chamber. It is for this reason that thev overr-flow valve' of the low pressure. stage doesnot have to be'a pressure loaded valve in ordertoprevent spilling at the over-flow when the injector is operating. 1 v l v The application of the present invention to an injector of the type shown in Fig. 1,, inia' man- .ner such that the "impulse for controlling the automatic live steam control valve is, derived communication With'the over-flow chamber '46 Con T from over-fiowrpressureis illustratedin' Figs- 3' and 4. In Fig. '3- a connection I2 is shownin nection 12' connects this chamber-with the actuating mechanism ofjan automatic valveE"; the construction of which is shown, inFig 4.

Referring now more particularly to Fig. 4, the

upper portion of the :valve, including the inlet i 7 and outlet chambers in the valve bodyj'and the mov able valve member including its actuating piston 84, is the same as that already described in connection with Fig. '2 *In the present valve arrangement, however, the pressurechamber flm with which the connection-12 communicatesis above the diaphragm 95 n which carries thepin V valve 92 rather than below the diaphragm as :in l

the former valve shown in Fig.2. In the pres pin valve away from itsseat'so asto ventch'ame entembodiment, the spring I00 tendsto hold the I j ber 86 and maintain the valve controlling flow through pipe 28 closed and" this conditionwill' obtainwhenever the low pressure stage 'of the injector is not operating with sufficientstability to produce the sub-atmosphericpressure in the over-flow chamberof this stage of the injector which occurs during normal operationfthereof.

If the low pressure stage of the'injector'is ,in'

-normal operation and is delivering water} tothe high pressure stage of the' injectorgapartial vacuum will exist inthe"over-flowi'chamber 01 e the low pressure stage, and' this partial vacuum, transmitted to chamberiBB' through the cohnection l2, will operate to close the pinvalve 92 :and effect opening of' the'va lve controlling flow v I in 'the manner already dethrough pipe 28, scribed.

From the above it will beevideht that the a i tion of the valve E- in the present embodiment in preventingbreaking of the'injector upon change over of operation, or at anyothertiniewhenlthe low pressure stage is not operating normally, "the same as that described: in connection vvit'h' Figs. 1 and 2..

In case an injector of the multip-le' -stage is designed sothat the low. pressure-'sta'geade- -livers water, heated: to a temperature abov'ekthe serially connected'with res pectto flow of water through the injector and comprising alow pres-,

sure; stage adapted to be operated by low pressure steam and a stageof relativelyLhigher pressure adapted to. be operated by steam; of higher pres-' sure than said low pressure steam, and valve means automatically operable in response to a pressure impulse indicative of stability of operationoi the low pressure stage for admitting opv erating steamto said stage of relatively higher pressure when the :low pressure stage is delivering a normal quantityoi water and for preventing admission of operating steam-to said stage of relatively higher pressure when the low pressure stage isnot delivering anorrnal'guantity of water. 1

3: apparatus ofthe characterdescribed com: prising a multiple .stage;;injectorhaving stages serially, connected with-'respectt fiow of water through the injector and comprising a low-pressure stage adapted to be operated by low' ;pres-' sure steam and a stage of relatively higher pressure'adapted to. be operated by steam of higher pressure than said low pressure steam, and valve means automatically operable inresponse toa iiuidpressure impulsegindicativeoi stability of operation of thelow pressure stage foradmitting. V operatingisteam' to said stage of relatively higher? 'pre'ssurewhen the low' fpressure stage is delivers ingv a ,normal quantity of water, and for prevent I ing f admission of operative steam to said stage of relatively higher pressure when thelow pressure sta'geis not delivering a,,r1o'rmal quantity of water.-

ifnpparatvs off the character described com: prising a multiple-stage injector having stages serially connected with respectftojfl'ow of water throughthe' injector and comprising a low-pres,

surestage adapted to be operated by low pressure steam'and astage of relatively higher pressurev adapted to be operated by steam of .higher pres sure'thansaid low pressure steam; conduitsfor supplying operating steam separately. to said stages, a, valve for, controlling flow of steam through theconduit supplying the stage of higher pressure, and'actuating means for said' valve operable in response to. an'fimpulse indicative of stability of operation of the low pressure stage for preventing flow of operating steam to the stage of higher pressure when thejlow pressure stage is not ,inta condition of stable operation; 1

5, 'Apparatusof the "character describedcomprising a multiple-stage injector having stages serially connected with respect to yflow of water through thein'jector and comprising a low pressure stage adapted to'be operated by low pres-v sure steam and a stage of relatively higher pres- ,sureadapted to 'be'operatedby steam of higherj pressure than said low pressure steam, conduits for supplying operating steam separately to said stages, a valve for controlling' fiow"ofsteam through the conduit supplying the stage'of higher" pressure, and actuating means responsive to deliveryp'ressure oi the low pressure stage for, automatically openings'aid valve when the low pressure stagefis' innornialoperation.

I 6 Apparatus of theoharacter described com- .prising a multiple-stageinjector" having stages serially connected with; respect'toifiow of water through the injector and comprising a low pressure stage'adapted to'be'operated by lowpressure steam and a stageof relatively higher pressure adapted to be operated by steam of higher pressure than said low pressure steam, conduits for supplying operating steam separately to said stages, a valve for controlling flow ,of steam through T theconduit supplying the stage: of higher pressure, and actuating means responsive I 9. Apparatus ofthe character described; om- 4 prising a multiple stage injector-havingaglow: 3 pressure stagev adaptedtobeoperated-by exhaust wto over-'fiow pressure of thelow"pressure stage .ior automatically opening said valve whenii thesk low pressure stage-is in normaloperation."v

v7. In injector :apparatusi having a pressure".

stage:toiwhichfwater is deliveredifrom a second stage of; lowergpressure, 'avalve' for controlling the:.admi'ssion of operating steam to the first" mentioned stage, and valve control means operable under the influence of afactorindicative;

of the condition of operation; of the-lowpresisure stage of the injector iorcausing said valve-f. to open;when the second mentionedstagejsfin 1 normal operation.

8. In injector apparatus: having a pressurestageto which water is delivered from'a second,

stageof lower pressure, a'valve for controlling the admission of operating steam' to the first mentioned stage, and operating mechanism asso ed with said valve .and operableunder the influence moi-Ha factor indicative of the. condition ofoperation of the low pressure stageof the in&

jector to cause-said valve-to permit operating-- steam-to be admitted to thefirst mentioned stage I when the second mentioned stage is in 1 normal .operation'and; to prevent the admission of operating steam to'the first mentionedst-age whenthe second mentioned stage isnqt'inlnormal opera:- J

steam and a high pressure stage adaptedto be operated by; live steam, conduits for supplying exhaust steam and live .steam to said-stagesre- -spectivel-y, ,a valve for controlling flow of steam:-

through the live steam oondu'it, ;and. meansresponsive to an impulse indicativefof stability of,

operation of the low pressuretstageof theinr jector fcr opening said valve when-the last me tioned stage isnot in stable operation.

exhaust steam and live steam to saidlstages rep 10. Apparatusof the character described com-g prising a multiple-stage injector having a lo w -j pressure stageadapted to /be operated by exhaust steam and a-high pressure stage adapted to be operated by livesteam; conduits for supplying.

' spectivelyQa valve iorcontrolling flow of steam -y 7 ,1

through the livesteam conduit, and pressure 1 8- i sponsive means' for automatically opening; said valvein response to establishment by the low pressure stage of a pressure indicative of stable operation of saidlow'pressurestage.

11.v The combination, with a multiple stage. f

jector having an automatic control system in eluding conduits for supplying exhaust steamer lowlpressurelive steam to the low pressure stage .of the'injector and high pressure live steam to the high pressure stage of the injector, of a valve proper operation jthereof;

12.In injector apparatus having apressure stage to which water is delivered from a second stage of lower pressure, a conduit for-admitting operating steam to the first mentioned stage, a valve for controlling flow of steam through said conduit, said valve being adapted ,to be closed by'pressurejof steam admitted tothe conduit, and

' tablishment by thezsecond mentioned. stageiof a r 7 pressure indieativeof. normal operationithereoi' for autornatically opening' said valve,

ing thej'first mentioned valveto open and pressureresponsive: means responsive to deliv'ery presoperating steam to the flr'st mentioned stage, a

pressureeresponsivemeans :responsive to the es- 13 ;f-In: injectorrapparatus' having r a pressu're stageitoiwhichzwater is delivered ir'om a second stage'nofq lower pressure; a :conduit -foradmitting I operating steamstdthe first mentioned stage ,I-a

v'alveeontrolling fl'ow of steamthrough 'said conduit; said valve adaptedto be closed by pressure of steamadxriitted t'o the conduit, steam pressure: actuated means-comprising a vent va'lve'f or caussure from th'e second' mntioned stage for actuat-' 'in'g: said vent valve;- 1

. 141 111 injeotori apparatus having: ipress'ure stage to whi'c'hivvater is delivered from a' second stage of lower-pressure, a conduit for adriritting valve controlling flow-of steam through "said 6on duit,'said" va1ve adapted to be-clo'sfed by pressure;

' v of'steamadmittedtothe'bondum steam-pressure actuating said vent 'valvefi 1 actuated means comprising a [vent valveifo'r c'aus- Qingth' first=mentioned valve to-openiarid pres sure responsiv {means responsive to f over-flow pressure fro'm the second mentioned "stagetor 15. fIn injeQtor apparatus, a high pressurestage,

i a lowgpressurestag'e for delivering watefto the highpressure sta'gegsaid low "pressure'sta'ge having an over-110W valve; means responsive {to {de- V livery pressure;of the'lowjpres'sure stag "for-loadi with'sa'id firstmentioned means for automatloali 1y"admitti'frig operating steam to: the high presing" saidiover-flow valve and means associated sure stage-When the first mentioned means-is I actuated'byidehverypressure toload said over-" flow-' valve andiorf preventing admission drop-1 4 erating steam to ltheghigh' pressure stage'in the 16! Apparatus or; the character desoribed cam prisingfa multiple stagefinjector; having stages" jse'rially' connected with; respect to fiow -'of water through-the injector'and Comprising a 10W pressurestage; adapted to be. operated by low pressure" stea'rn' anda sta'lge of relatively higher pres-'- sure adapte'd to be operated'bysteam of'higher pressure than saidjlow pressure st.eam,-a conduit' enablem responseto deHvery of at -pr'ede' tenninedaipressure Item; the dew: apres'sure stage 'tothe} supplyingsaid$steam n U y lastmentioned stageyand an"utomatic valve n 7 19; Apparatus-:01;thecharao'terdescri d ooni prising? a'yrnultiplesta' V pressurestag'ejadapted'fto be operated "in; a

stezaurl irom arifengineand a; high pre'ssure stag ad'ai'ate'd 00" he operated by high? press e-111 steam and reeeivingfwater; deliver'edflfroin saidg' 7 low pre'ssure stage; a low pressure steamfcon'duiti 30 i for v e n iloweg nes ion ra ns-a e m" t 1 for delivering high pressu pressure stage; a manuallybperahle;control valve inesaid h i'ghpressure'conduitifan automatic valve; in saidh'vigh pressure-conduitjbetween themanu- '1 v thehigh pressure StaKQ-M I associated with tnew ive;meiclbsan tne and-:43 ssure responaive moans autmnaticallyiop Amie-mamas or the fl ndescnbee at,

prising a; multiple; stage ammo: having stages serially I c'onnected' withf resbeet' to fiow of' watfie through theinjector arid comprising alovv pmsl0 sure stageadaptedto b-perated liy lowjress'ure' surethansaid lovipressurefsteani a conduit said- Conduit rpr' "admitting; pe r'atin said stage of relatively higherpre'ssd n V lowpressure 'stage- 'isfsupplying waterthferetoand sure stage is not supplying wa-tenthereto; :1

i c o' ha'vm fgh. pressure 00min t said low: pressure Sta U V V s amo samf l h,

ally operable valve and'l'said high; pressure st'ai means for, causing [said automatic valve Y to. re main closed when s'aidlowpressure staejfis fnb delivering water to the 3 high pressure stage,: an

mean'shfor oausinggnsaid automatic va ve to open when thelow pressurestageis dliveriihgwatixtb.

-steam and aflstage 'of relativelyghigher fpressure 1 adapted to.=be operatedbyf'steam of highebpres 4dr {shutting off operating-steam front saidstage 120 'of relativelyhigherpressure'gwhen the'lqw pres- 20'. Apparatus ,of th 'charaoter' prising a multiplejstage,iniectorfhavihe a' l'o w i nation eby low prjessureJive; steam,.o1'fexhaust steam from an' engine ,andi'a 'highipressuri stage It,

adaptedto be j operated by] highfbressuremflive n V steam and l,receiving,..vvate1 'f delivered. from said .3

50 v i V v v pressure stage, a 1ow pressure steam. .conduit-; I,

eri "low-pre s re. operating iistea'mf to'p said .lowj pressure stage, a high pr ssure vconduit 1 forisupplying said steam of higher pressuretothe: last mentioned stage, a valve'for' controlling flow 1 of steamnthroughsaid"conduit, and pressure'ree sponsive means for opening said valve in response f to delivery of watenat predetermined pressure 1 by saidlowpressure stag'e t'o thestage of. higher, :pre's'slim i.

17; Apparatus ofith'ef'character deserilbed 'com prising iajmultiple stage: injector having stages rg s'erially -connected.with'respeet to new of water through theinjec'tor and eon pr isi n' g a. low pressur'eistafge adapted tobe operated by low pres ,sure steamand a stage of relatively higher pressure adapted tone-operated; bysteam oi higher.

7 pressurethan said low pressure" steam,1"aconduit for supplyin'g*- said steam "of higher bressu're 'to '7 the last mentioned stage, a valve in's'aid conduit" for controlling flow of steam therethroughfmeans I waterto'theghigh pressure stage; aeaiaie nnecfibn V for supplying steamgtojsaidldw 'pressurezeonduit" from said. high .prssuree'onduit, saidleonne'otion j communieating', with v the lipmifidr l of v. high 65 F for v delivering'.,-,high pressurefsteain i-to ,said highif j manually operable. valve. and said. m npnessur stage; saidgautomatioivalvef operating to shutlbfi t "the Z steam r supply to, sa1dj..h gh. pressure .stage; 60 a when the. low: pressure Ljstag'ei is gnotkdelivering pressure conduit hetjveeiii said'valve's; i V

."pressure stage, a oiierahl'epoontrol'yalve L 1. in saidhigh pressure oondui t anrautomaticivalve. .j located in saidhighprssfurejconduit between sai 

